<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>单列布局-垂直居中</title>
	<style type="text/css">
		.wapper {
			background: #000;

		}
	
		/* 11<20 */
		.wapper div {
			color: #f00;
		}

		.wapper .box,.wapper .box1 {
			font-size: 15px;
			color: #fff;
			border: 1px solid #f00;
		}
	</style>

</head>
<body>
	<div class="wapper">
		<div class="box">我是box</div>
		<div class="box1" id="box_1">我是box1</div>
	</div>
</body>
</html>